Weldernator

I ran a Weldernator(GM alternator modified to weld) and it worked well. If anyone isnt familiar it is a GM Delco alternator(mine was sm case) with the diode bridge removed, the voltage reg. grounded(full volts all thie time) and 12 volts to terminal#1 the case is ground and the output stud is your stinger. This worked well for trail fixes and I know there are better on board welders available just none im willing to pay for after seeing how well this worked. My question is could this be spun backwards and still produce electricity? My current setup would require me to use the weldernator as an idler pulley on my 4.0L The one below the AC bracket. I could turn down a pulley so the back side of the belt would turn it and hopefully weld stuff (trail only of course) It wold be a fairly in depth bracket to fab so if anyone fully understands alternators let me know if they work backwards before i build said bracket that would be great. Thanks in advance.

Electrically it can be spun backwards. Reverse rotation shouldn't be that big of a deal on the brushes, but it would't hurt to install new ones.

Kinda curious, what rod do you use, what size? What kind of output are you seeing, duty cycle?

Its was a 90amp alternator. I use 5/32 rod and it needs about 2200 rpm ( your application may vary) and i welds very nicely. It works well for trail fixes. I would say 100% duty cycle because these alternators are made to produce at least 90amps all the time right? Now as a side note it does get pretty warm(the case) but im sure a regukar alt. does too ive just never checked.

could you post a pic if the diode bridge, and what is the alternater out of?

The "diode bridge" was actually removed in this case (since the diodes tend to pop at about 25-30VDC, and you need up around 90VDC for a good fusion arc...) and you can use pretty much any Delco job for this. I'm thinking of talking to Rod to see if he can offer a "weldernator" for mail-order as well - if he builds them with his customary quality, they should be damn near indestructible.

WARNING - if you weld with something that is actually on your vehicle at the time, make sure you have the ground to the chassis/part, and the hot on the stick - not the other way 'round. Even if the alternator is setup as a separate electrical system.

Feeding +VDC through the chassis can cause a feedback that will cook critical electronics...

5-90

if you spin it backwards the fan won't do a very good job of cooling it

As far as spinning it backwards - why?

The alternator is already spinning in the direction it needs to to generate electricity. Spinning it backwards may or may not reverse the polarity of the electricity being generated (which would be bad.)

Besides, you don't want to use it to generate electricity for your vehicle - with the diodes removed, you'll get WAY too much voltage (especially with the regulator shorted to ground!) and you'll end up blowing every semiconductor you have. Not fun.

5-90

The diode bridge it what makes the alt. produce DC current with it removed there is no polarity its AC. As for spinning it backwards that seems like the easiest way to fit both a York comp. and a weldernator on the same bracket. Id use the York in the place of the sanden comp and then replace the idler/fan pulley with a weldernator running on the back of the belt and run dual elec. fans. You are right i would get too much voltage w/ reg grounded if it was being used for charging but from reading your post im able to deduce you didnt read mine

Entirely possible - it's been a frustrating day. You are correct - you're still getting AC without the rectifiers, my mistake.

In that case, it probably will not matter that you are going to spin it in reverse (I guess you're going to run it on the backside of the belt?), since AC is AC. It's only a problem in household - since you have two "hot" leads and one "neutral" or "return" lead - not the case here, since there are only two leads.

Since the alternator uses "slip rings," rather than a "commutator ring" - and there is no need to change polarity, there are no interruptions in the slip ring, which should allow smooth brush operation in either direction.

5-90

Thanks man that what i thought but wasnt sure